Warming driving accelerating river erosion in Bangladesh

A resident of East Bahuka village in Bangladesh’s Sirajganj district shows where land he used to own was lost to growing erosion along the Jamnua River. THOMSON REUTERS FOUNDATION/Syful Islam

SIRAJGANJ, Bangladesh (Thomson Reuters Foundation) – Worsening erosion along the banks of the Jamuna River has dramatically increased the number of families losing their homes and land – but dredging could help ease the problem, experts say.

Erosion is a long-standing problem in Bangladesh, with much of the country made up river deltas deposited by the region’s many rivers. But more extreme weather and heavy runoff has led to growing deposits of soil in the Jamuna River, which is in turn driving worsening riverside erosion, residents and experts say.

This rainy season alone, hundreds of families in Sirajganj district have lost their homes or their farmland, they said.

Amir Hosen, 70, of East Bahuka village, said he had gradually lost all of his two acres of land to the river, and now has had to rent about a tenth of an acre of farmland to house and support his family, at a cost of $70 a year.

“I had to move three times with my belongings as the Jamuna River continued eroding. I was a land owner. Now I have become a refugee,” said Hosen, the father of three daughters and two sons who have had to leave the area to find jobs.

He said erosion of river-side land now happens throughout the year. “Earlier, we saw erosion in April- May season, but now it is eroding throughout the year,” he said.

Atiq Rahman, executive director of Bangladesh Center for Advanced Studies (BCAS), told the Thomson Reuters Foundation in a telephone interview that due to formation of char – land that emerges from riverbeds as a result of accumulating deposits of sediment – rivers like the Jamuna now store lower volumes of water than in the past.

That leads to displacement of river water, with more of it pushed against the riverbank, leading to worsening erosion, he said.

“Getting no other option, water starts hitting the river banks as the flow increases during the rainy season, causing erosion and making people landless,” he said.

DREDGING AN ANSWER?

He believes that large-scale dredging could restore the depth of the riverbed and increase its ability to hold water, cutting the rate of erosion.

Dredging on the Indian side of cross-border rivers like the Jamuna, the Padma and the Brahmaputra means losses of land to erosion are much smaller there, he said.

“The rivers there (in India) are stable while here these are very much unstable,” he said.

But the soil makeup is also playing a role in Bangladesh’s more severe erosion, he said. Riverbank soils in India contain more rock, he said, and have more resistance to the erosive forces of water. Bangladesh’s riverbanks, however, have few rocks.

Some embankments in Bangladesh are strengthened with stones or concrete slabs, but not all have been properly maintained, he said. For such protections to be effective, “the maintenance costs have to be an integrated part of an embankment construction budget so that steps can be taken immediately when signs of possible erosion emerge.”

Jail Hossain, a member of Shuvogacha Union Parishad, a local government body, said the Jamuna’s erosion had eaten up three villages in 2007, forcing 2,000 inhabitants to move to Bahuka village.

In 2009 and 2010 they were again displaced by erosion and forced to move towards East Bahuka village. In 2011, the main Bahuka village was totally lost to the river and now East Bahuka village is also being eroded away.

Abdus Salam, headmaster of Chandnagar primary school, said the whole of Chandnagar village was eroded by the Jamuna River in just one year and the school had been forced to move a kilometer away to East Bahuka village, now itself under threat.

“This year the intensity of erosion is very high and I am in doubt whether any portion of this village will be left intact,” he said.

EMBANKMENT PROBLEMS

Aynal Mia, a farmer of the village, said the Bangladesh Water Development Board (BWDB) is focused on building new embankments but has not done enough to stop the continuing erosion.

“You see work on a new embankment going on, leaving a big part of the village for the river to eat up, instead of (workers) taking measures to protect the existing embankment,” he said.

Anisur Rahman, a sub-divisional engineer of the water development board, told the Thomson Reuters Foundation that erosion has washed away three entire embankments in the sub-district since 1971, when Bangladesh gained its independence.

He said due to a lack of maintenance funds the board could not protect existing embankments with stones, sand bags, and concrete slabs. He agreed that river dredging was needed.

“Necessary dredging in the river can help storage more water by the river and protect the embankment from erosion,” he said. He noted that “erosion nowadays is much faster” than in the past.

Rahman, who was born and brought up in this area, said the changing river depth was evident from the types of ships that could navigate it.

“During our childhood we saw big ships were plying through this river. The depth of the river was nearly 100 feet then. Now it is reduced to 25 to 30 feet,” he said.

Fazlul Huq, a sub-assistant engineer of the water development board, said his agency needs Tk 1.5 billion ($1.5 million) to carry out a proper maintenance work to protect the local river embankment.

“But we don’t have such a budgetary allocation. So, we are now building an alternative mud wall so that water can’t enter the remaining part of the village this season,” he said, admitting such work was a short-term measure.

BCAS’s Rahman said the worsening erosion was in part of a result of climate shifts which have led to more rapid melting of ice in the Himalayas. The increased runoff carries additional sediment into the beds of rivers such as the Jamuna, leading to increased riverbank erosion.

Syful Islam is a journalist with the Financial Express newspaper in Bangladesh. He can be reached at: youths1990@yahoo.com

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